1. Field of the Invention
This invention relates to a method of covering a roof with sheet roofing material and to the roofing system formed thereby, and in particular, to roofing which is mechanically attached to the roof such as by screws or nails or the like.
2. Description of the Prior Art
Applying a roof to a static structure usually comprises applying sheets of roofing material to the structure over the existing roof or subroof. To secure the sheeting material to the roof, a mechanical attachment is needed. Usually, this mechanical attachment is obtained by using nails or screws which are driven through the sheeting material and into the roof beneath the sheeting material. This mechanical attachment, however, produces undesirable holes through the sheeting material through which the nails or screws extend. The exposure of such holes results in a finished roof which may be prone to leak sooner than a roof without such exposed holes.
To reduce the number of holes, it has been prior practice to overlap the sheets of roofing material and to drive the nails or screws through the double layer of roofing material along the overlap. This reduces the number of holes in the sheeting material and thus reduces the possibility of leaking through the roof. Exposed holes, however, are still present in the finished roof. Another possible solution has been to apply sealer individually to each of the holes. This solution, however, is time consuming and expensive.